γ-氨基丁酸B受体抑制大鼠肝细胞迁移并改善肝纤维化

γ-aminobutyric acid B receptor （GABABR）ameliorated liver fibrosis by inhibiting hepatic cell migration

目的探讨发现γ-氨基丁酸B（GABAB）受体对肝纤维化的调控作用。方法32只SD大鼠分为4组，每组8只，分别为对照组、模型组、baclofen处理组和CGP35348处理组。用四氯化碳（CCl4）溶液诱导肝纤维化，baclofen和CGP35348处理均在肝纤维化形成后。摘眼球取血测肝功能。留取肝组织标本，分别进行组织学染色、免疫组化、实时PCR和Westernblot实验。结果组织学结果显示CGP35348组肝纤维化程度明显重于baclofen组（P《0．001）。baclofen处理组丙氨酸转氨酶（ALT）、天冬氨酸转氨酶（AST）、γ-谷氨酰转氨酶（GGT）、总胆红素（TBil）以及直接胆红素（DBil）血清水平均显著低于CGP35348处理组（P〈0．01）。CGP35348处理组ALT、AST、GGT、TBil以及DBil血清水平亦显著高于模型组（P〈0．05）。免疫荧光结果提示baclofen处理组肝细胞迁移能力明显抑制。Westernblot结果显示baclofen组α-SMA水平显著低于CGP35348组和模型组（P〈0．01）。结论本研究首次报道baclofen对肝纤维化的保护作用，可能主要是通过抑制肝细胞的迁移能力而改善肝纤维化。

Objective To investigate the role of γ-aminobutyric acid B receptor in the development of liver fibrosis. Methods Thirty-two Sprague-Dawley （SD） rats were divided into four groups including a control group, a model group, a baclofen group, and a CGP35348 group. Liver fibrosis was then induced by carbon tetrachloride （CC14）. Baclofen and CGP35348 treatment were carried out after the formation of liver fibrosis, followed by complete extraction of the eyeball to obtain blood sample to test liver function. Liver tissue specimens were cut and stored for histological staining, histochemistry, real time polymerase chaiwreaction （RT-PCR）, and western blot analysis. Results Histological staining indicated that the degree of liver fibrosis was more severe in the CGP35348 group than in the baclofen group （P〈0. 001）. The levels of alanine transaminase （ALT）, aspartate amin- otransferase （AST）, gamma-glutamyl transferase （GGT）, total bilirubin （TBil）, and direct bilirubin （DBil） were significantly lower in the baclofen group than in the CGP35348 group （P〈0.01）. The levels of ALT, AST, GGT, TBil, and DBil were significantly higher in the CGP35348 group than in the model group （P〈0.05）. Immunofluorescence results show that the hepatic cell migration was in- hibited in the baclofen group. Western blot results showed that the expression levels of γ-SMA protein were significantly lowered in the baclofen group when compared to that of the CGP35348 group and model group （P〈0.01）. Conclusion GABAB receptor might play a role in the liver protection by in- hibition of migration of hepatic cells in liver fibrosis. Further studies into the mechanism behind this function are further needed and may be a potential source of future anti-fibrotic treatment.